The US Supreme Court earlier this month heard oral arguments in a case that will set the legal boundaries for police GPS surveillance of automobiles. Last year, the US Court of Appeals for the DC Circuit ruled that police were wrong to spend a month tracking the every move of Antoine Jones, who was arrested on October 24, 2005 for drug possession (view opinion). A tracking device had been attached to Jones’s Jeep without judicial approval. The high court judges engaged in heated debate about the rights of motorists in connection with the Fourth Amendment.

“It seems to me the heart of the problem that’s presented by this case and will be presented by other cases involving new technology is that in the pre-computer, pre-Internet age much of the privacy — I would say most of the privacy — that people enjoyed was not the result of legal protections or constitutional protections; it was the result simply of the difficulty of traveling around and gathering up information,” Justice Samuel Alito summarized. “But with computers, it’s now so simple to amass an enormous amount of information about people that consists of things that could have been observed on the streets, information that was made available to the public.”

The administration, represented by Deputy Solicitor General Michael R. Dreben, argued that police do not need to obtain a warrant because location information could have been obtained this information through ordinary surveillance methods. That means anyone could track even supreme court justices without violating their privacy.

“So your answer is yes, you could tomorrow decide that you put a GPS device on every one of our cars, follow us for a month; no problem under the Constitution?” Chief Justice John Roberts said. “Your argument is, it doesn’t depend how much suspicion you have, it doesn’t depend on how urgent it is. Your argument is you can do it, period. You don’t have to give any reason. It doesn’t have to be limited in any way.”

Roberts suggested the process of obtaining a warrant serves as an effective limit. Scalia seemed to suggest that state legislatures were best suited to decide what limits should be placed on police tracking, not the courts. Other justices worried about the implications of allowing unrestricted tracking.

“[It’s] an easy way, to pick someone up for speeding when you suspect something far worse but have no probable cause,” Justice Ruth Bader Ginsburg said. “It’s all in the computer. The police can say, we want to find out more about X, so consult the database, see if there is an indication that he was ever speeding in the last 28 days.”

Justice Anthony M. Kennedy compared the GPS tracking to the use of speed cameras and red light cameras for tracking purposes.

“Lots of communities have, including Washington, cameras on — at intersections on stop lights,” Kennedy said. “Suppose the police suspected someone of criminal activity and they had a computer capacity to take pictures of all the intersections that he drove through at different times of day, and they checked his movements and his routes for five days. Would that be lawful?”

Justice Elena Kagan suggested constant police surveillance of an individual is obviously a violation of privacy.

“If you think about this, and you think about a little robotic device following you around 24 hours a day anyplace you go that’s not your home, reporting in all your movements to the police, to investigative authorities, the notion that we don’t have an expectation of privacy in that, the notion that we don’t think that our privacy interests would be violated by this robotic device, I’m — I’m not sure how one can say that,” Kagan said.

Scalia seemed to suggest that state legislatures were best suited to decide what limits should be placed on police tracking, not the courts.

Ah, classic Scalia. “Yeah, sure, states should be allowed to track you however the hell they want. Why are we even having this argument, anyway?”

Still, if even Roberts is against warrantless GPS tracking this whole thing might sink. Here’s hoping, anyway. The fact that Kagan is the only one who immediately says “What? No, get a warrant.” is worrying.

edit: though I have to say, Kennedy’s little quip there is sobering, and not because of what way he’ll vote. He’s basically pointing out “what, is the objection that they’re physically planting a tracking device on your vehicular property? Because with a camera at every corner and some plate-reading software, they can track you without touching your vehicle at all.”

There’s a hell of a lot of things disturbing about this; like arguments about “fighting terrorism” without due process the idea of doing away with even basic oversight to government police powers is terrifying.

There’s a damn good reason the USA faced down both the Nazis and the Communists without changing the basic system of judicial oversight.

there is something i don’t get here. all these arguments are based on the expectation of privacy. to me, the obvious violation is the police physically attaching something to my private property. what gives them the right to do that?

Because the Supreme Court has lately been leaning towards the idea that the one and only place you are entitled to privacy is within your own home. As soon as you walk out the door your expectation of privacy should be nill. I wager they’ll uphold unwarranted gps tracking.

There’s a very good write-up of oral arguments at http://www.scotusblog.com/2011/11/argument-recap-for-gps-get-a-warrant/ :

“The argument in the much-anticipated case of U.S. v. Jones left a solid impression: the Court, though it is unsure just how much privacy remains in the new digital world, does know just enough about the GPS device to see in it a considerable threat to people’s right to be let alone. The occasional suggestion during the argument by Justice Antonin Scalia, that state legislatures can deal adequately with such a threat, did not appear to be anywhere close to what the majority was thinking. He belittled the idea that a ‘scary’ police tactic could be a constitutional problem, but most of his colleagues fretted that it might well be.”

There are already devices that detect GPS transmitters. So I foresee a business developing in GPS detection – maybe add it to a car wash – would you like GPS detection and underbody flush?

Then give the unit to the driver or toss it in the trash. With budgets as they are I don’t see millions of these things being slapped on cars. Of course, there is the argument that the GPS belongs to the police, but it could be argued that they abandoned the device on the vehicle, no longer in their custody at that point it was placed and they left.

Look, cameras at every corner stoplight and along stretches of highway can already OCR your plate, just right now they’re only used for catching red light runners and speeding violations. It would not be technically difficult to have a sufficiently pervasive networked camera array track every car everywhere at all times, just by reading license plates. The software would be slightly tricky but probably not as tricky as the software to pick up a GPS signal on an embedded microcontroller.

If you have privacy complaints it’s a bad, bad idea to focus your complaints on the GPS hardware dongle stuck to the undercarriage of the car; that’s a technical problem that they can work around.

while I agree with Aristurtle, the thing people forget is even though in the grand scheme of things this is small fish, precedents are a powerful force in the supreme court world.

If you say right now, that gathering this intimate level of detailed information constitutes a search and without a warrant, that’s a violation of the 4th amendment. Then it would be easier to say that storage of information with the purpose of tracking where a car has been via cameras could be an unconstitutional search. kinda like how the TSA was supported to not store images from full body scans (even though they openly admitted to doing it.)